Some fluoropolymers, such as poly(vinyl fluoride), are only moderately soluble in conventional solvents. According, such polymers are generally cast into their final configuration from a dispersion, and coalesced to form an integral structure.
In the preparation of poly(vinyl fluoride) films for which a high degree of clarity is required, the use of propylene carbonate as the solvent or dispersant has been found to be particularly useful. However, while films and coatings prepared from propylene carbonate dispersions are generally characterized by excellent clarity, occasional defects, in the form of pin holes or "fish eyes," result in yield loss.